Pressure actuated collet-type chuck



July 24,, 1951 E. G. SMITKA 2,562,134.

PRESSURE ACTUATED COLLET-TYPE CHUCK Filed July 28, 1949 2 Sheets-Sheet 2 EDWARD 551*1/7764 INVENTOR.

Patented July 24, 1 951 1 UNITED STAT PRESSURE ACTU ES PATENT OFFICE ATED COLLET-TYPE CHUCK Edward Grsmitlia, Chicago, Ill.

Application July 28, 1949, Serial No. 107,345

9 Claims. (01. 279-4) to a new and novel col-- this principle have employed a piston movable within a chamber in order to produce the desired results. However, these prior means for transmitting a fluid pressure have not been entirely satisfactory because of inherent inadequacies in the' means employed which were responsible for a leakage of the pressure transmitting fluid. It is therefore an object of my invention; as will be more particularly illustrated and described herein, to provide in a collet-type chuck a means which will preclude the leakage of pressure transmitting fluid. It is an object of my invention to provide a means for transmitting fluid pressure including a completely enclosed chamber, an integral wall of which is movable.

Investigation of the references in this general art has led me to believe that prior devices of the same class as mine have been "required, in order to operate, to maintain the fluid pressure during the entire period when the gripping ac tion of the collet was required. This necessity has a distinct disadvantage in that leakage or stoppage of the fluid pressure through the conduit from a source would produce an impairment of the operation of the device because the gripping of the collet could only be effected when the pressure was being appropriately applied. It is an object of my invention to provide a combination of elements which, once having been forced into appropriate positions by the fluid pressure, cause a locking of the elements involved to maintain the collet in gripping position and which will cause the collet to be maintained in gripping fposition after the pressure has been removed. It will be understood that by thus providing a means which precludes the necessity of a continuous fluid pressure great efliciency and saving is achieved. It is additionally an object of my invention to provide a means for adjusting the collet with relation to the locking mechanism so that as the parts of my device wear compensation may be made for such wear so that maximum efliciency'will be constantly reached.

-' It is additionally an object of my invention toprovide a system of levers through which the fluid pressure may be transmitted so that the mechanical advantage of the collet is multiplied to enable the collet to grip with a force which is greater than that of the fluid pressure.

Inasmuch as I am providing a pressure actuated collet-type chuck device which will operate after the actuating pressure has been removed, it is also necessary that I prOVidG a suitable means for causing a release or unlocking of the jaws of the collet. ,Therefore it is a fur-.

ther object of my invention to provide a pressure actuated releasing mechanism including an expansible chamber, an integral wall of which is movable, for causing an unlocking of the jaws of the collet.

beveled or tapered seat or flange which is adapted to have the jaws thereof moved to gripping or non-gripping positions andhaving a, suitable actuating mechanism for accomplishment of the. said movement of the jaws'and having expan-' sible fluid operated bellows for actuating said last mentioned mechanism to produce the desired result. Y

Other and further objects of my invention will become apparent from the following description and appended claims reference being had to theaccompanying drawings and numerals of reference thereon.

On the drawings:

Fig. 1 designates a cross-sectional view taken on a vertical plane and passing through substan tially the center of my device. I

- Fig. 2 designatesa. sectional view of my device taken substantially on the line 2-2 and looking in the direction of the arrows.

Referring to'the drawings, Fig. 1, it will be. seen that numeral l0 designates any standard or.

lathe spindle l0 rotates sleeve IE will also rotate.v Sleeve I2 is preferably provided with an inwardlyextending annular flange l3 and it will be noted by referring to Fig. 1 that the inner wall of saidflange is tapered or beveled as indicated at [4 to provide a seat for the slidably gripping jaws of collet l5 which will hereinafter be described. It should be'understood that the flange [3 does not necessarily have to be formed integral with sleeve l2 and that under certain conditions of manufacture and of use it is preferable thatthe flange l3 be-provided' by a separate non-integral member. However, whether'or not flange l3is' formed integral with sleeve I2 is a matter of choice and it should be understood that in any event the inventions hereinembraced would not be affected.

It will be noted by referring to the drawings that numeral l6 designates the outer shell on housing of my novel chuck. The outer shell I6 may be made "of any appropriate or suitable material. Numeral l1 designates an apertured rear plate which is retained in appropriate relation to the housing I6 by any suitable means and it will benoted. that t facilitate retention of said rear Additionally, it is an object of my. invention to provide a collet slidable within a plate or base I1, I provide a suitable lock nut designated as numeral I 8 which in the form illustrated here is threaded on an end extension of sleeve I2f=and%:thatI-..use suitable screws 25which are threaded into housing I6 as illustrated-in Fig. 1.

As illustrated in Figs. 1 and 2, it will be noted that the sleeve I2 is provided with arplurality-oft holes or their equivalents I9, one of which is:

clearly illustrated in Fig. 2, and a plurality of inwardly opening apertures 20 which are communicatively connected to respective'holes I9- In each of the holes I9, a pin or pintle 2| is pivotally mounted and a lever arm 22 is secured toeach of the pins 2|. Each of the levers 22 is provided with an end ear-or-lug 23and-an end ear "or lug 2'4 which= will be hereinafter morefu'ily described;

" Numeral 26 designates anormallydownwardly" extending aperturedlobe or lug which is-provided By referring to Fig. 1, it

an aperture 2'1.- will beseen-that an'anchor stud 28 is adaptedto be slijdably mountedin* the aperture or opening 211' In one form-of my device I employ the' anchor stud 28-"to' maintain the housingfrom rotation and displacement -and this is a'cc0m-'-- plished bythreadihgthe threaded end 29 of stud- 2 3 '-*-irit o the head *stock housing of the-lathe not shown); Numeral 3U represents a front plate ormember which is mounted in-itsappropriate po s ition, as illustrated in Fig. 1 of my device; and" it will be *seen "that in "the form illustrated herein r employ screws" 3I; oneofwhichis illustrated,

t6 retain the front" plate securely against" the housing-or shell"I6; Referring-to Fig."- 1, it will be seen that I provide an annular partially en closed chamber 32. An expansible corrugated member" or annular bellows 33; preferably comprising an 'outer corrugated tube33a and an inner corrugated tube 33b, is positioned-"within thecharnber 32 and it will be notedthat therearmost portlon'of the'bellows '33-is preferably rigidlyconnected to rear plate I! 'byany suitable means. It should be observed that'a' conduit 34 -"communicatively connects the-chamber of bellows 33 with arrappropriate fluid-supply'source: It shouldalso be' observed that the bellows 33"is positioned around 'andioutwardly of the sleeve I 2."

Numeral 35 designates a forward or front 'par=- tia lly' enclosed chamber and positioned within said 'ch'amber 35 is a bellowspr expansible *corru gated member 36 whichpreferably comprises'an outer corrugated: tube 36a and. an inner corrugated 1 tube 36b; Tubes 36'a and 36b: are rigidly seeured toi-the fronttplate: It vwillbe observed that in :the preferred "form illustrated; herein. theoute'rihousing I 6 .isxprovided.withafanfinwardly extending annularfiangefi'! whichxpartially divides the interior of theschuck :into partially-enclosed.

chambersi32;and 35:

Ring 'orannular plater-3B"is slidably'mounted; on

sleevevl2 and itwill be seenthat the ring- 38* is 4 the rings 38 and 39 do not function as pistons but as a force transmission means which hermetically seals the chambers of the respective expansiblelbell'ows.

Numeral 40' designates anannular lock lever which is slidably mounted on the sleeve I2. The lever 4|] has an inwardly extending flange M and saidr-lever-Aflris provided with an annular bevel orztaper cam face illustrated as 42. The operation of -lock ring 40 will be described at greater length hereinafter.

As. illustratedjnthe drawings, numeral 43 represents an annular internally threaded thrust sleeve which is slidably mounted within the body sleeve I2, which is provided with a plurality ofrec'esses 50 -intowwhich lobes.-24-normallyyextendasillustrated in: Fig: 2, and-it isto be undere stoods. that during; the normal :operation of my: novel. device the thrust sleeve" 43 is retained: fromrrotation independent; of ;body" sleeve 1 Zi'dlle to. the. coaction of lever, lobe 24:. withwtheewallsr of. recesses 50"in:thrustsleeve43.;

Numeral 44 designates anadjusting: sleeve: Whi'shris :adjustably threaded; into thrust," sleeve. 43 and which is; alsopreferably internally-threads ed; Numeral I5; as-previously-indicated;rcpree sents--a collet-havinga plurality of jaws-which? are: adapted: to be: shut tight upon: a1 pieceool. workj and: to--be retained thereby: It will: be :Seen r thatgtheendgstem or shaft of:;col-letI S is; provideed; with'rthreads 45*andthat saidccollet ,is:-there-.-- by, adapted: 1 be: threaded: into the adjusting; sleeve-44.

Numeral. 46 designates,azplurality ot apertureas holes or openings whiclrare preferably; annu-lare-i 1y spaced in adjusting sleeve 44; Numeralrfli illustrated. in Fig. 1,- representsia pin: which! extendsinto: one of .the: apertures, to tretainzadm justingsleeve sue-from independent .rotatiom It: shouldbe noted, that thelobes ;24 oflevers 22 tially; extend; into 13116551050949 provided :betweem thrust sleeve-43 and. adjusting sleeve 44;-.

In order: toiimore readily;appreciatesome :otr themaior concepts of m-y inventionrI; shal-lbriefiy. describe the manner inw-hichzthe formaof my invention:hereinsdescribed operates: v

It -.is--to be understood thatrwhenzxfiuid pressures is. transmitted through the conduit 34 through suitable conduits (notrshownl from avfluid pr s sureisource inot shown) that .thebellows 33 wilL expand. longitudinally. The expansion or bellows: 33 causes plate: 38tol move-forward; The ;obvious-; advantageaof providing-inwardlyextending flange? 31 v is now apparent and zit-will be. noted: that: flange3'! is-adapted tostop thesnormal movement: of the: plate 538 so-that the bellows 33 will not be? stretched beyond the desired limit. Asthe plate:: 38 -moves. forward it is forced into-engagement: with lock ring.40;=to:-movesameto the position which :is illustrated -in;Fig-; 1. The normally; frica tional engagementof the lobes-23 ;of lever or arm: 22v with; lock ring -40-'.issu'flicient' to retainssaidr lock. ring-g-from: slipping. back during the normal? operation. of my device and therefore it is-possible; after the lever ZZ-rhasbeen-pivoted; becauseioiz engagement with lockring-40;- tocutoffiorstop the pressure required; to forceslook ring: 401 1012-2 ward.= This enables my device to.- operate: without theimpediment of the fluid Dressureforceand: therefore: precludes undue wear whichwouldzarisa from operation of my device under pressure; Thei engagement-coir lockring-MI lobe-23 causes thelever- 22 :to pivot to thereby cause the ears :24; of'levers. 22 to. similarly be-mevedrearwar blr lna muchzas the ears; 24 rare: insengasementvwithi the thrust sleeve 43", the rearward movement or said ears causes the thrust sleeve to be forced rearwardly thereby'drawing adjusting sleeve 44 and the collet I5 rearwa-rdly. The rearward movement of collet' l5 is adapted to cause the jaws of said colletto close and impinge upon any work which is-pos'itioned' in the bore of said collet.

In order to release the work from the jaws of the collet l5"-"pressure" is'transmitted into the bellows 36 through-the :conduit '4 8:.fr,om an appropriate source. This pressure, causes the bellows 36 to expand longitudinally to thereby cause the movement of plate 39 rearwardly against the forwardedge of lock ring 40. The annularfiange 31 is adapted to stop the rearward movement of the plate 39. However, when the plate 39 has been stopped from any further rearward movement it has caused a disengagement of the lobes 2 3j from the lock ring 40,- Therearward movement of ring 40 during-the'unlocking process is sufficient to permit'a pivoting ofthe levers 22 so that the lobes 24 of levers 22 release the looking pressure against thrust sleeve 43 to thereby permit the normal spring pressures of the collet jaws and body to move the collet outwardly to a normal open position.

Prior inventions in this art have been devoid of any adjusting mechanism to compensate for wear of the component elements. My novel invention, however, provides an adjusting mech anism for the compensation of wear in the mechanism involved in locking and releasing the collet. When it is desired to adjust the collet the pin 41, which is adapted to retain the adjusting sleeve from independent rotation, is removed and the collet l5 which is securely threaded into the adjusting sleeve to retain said collet from any further rotation independent of adjusting sleeve 44, is rotated together with adjusting sleeve 44 to cause the same to thread rearwardly in the thrust sleeve 43. It will be seen that this adjustment causes the space designated as 49 between thrust sleeve 43 and adjusting sleeve 44 to become smaller so that a lesser movement of the levers 22 will be required to move the collet l5.

It is to be observed that I am able to achieve great mechanical advantage in my device as a result of the ratio of the distance between the cars 24 and the pin 2! and the cars 23 and the pin 2|.

As many changes could be made in the above construction, and as many apparently widely difierent embodiments of my invention within the scope of the claims could be constructed without departing from the spirit and scope thereof, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a collet-type chuck having a housing, a means within said housing providing a seat, a collet engaging in said seat, and having movable means for changing the relative positions of said seat with respect to said collet, characterized by an expansible means within said housing and having a chamber communicatively connectable to a fluid pressure source and being adapted to actuate said movable means, said expansible means being expansible and having an integral wall thereof movable to affect a movement of said movable means to thereby cause the jaws of the collet to close or open.

2. In a collet-type chuck or the like having a housing, and means within said housing providing a tapered seat, a collet engaging in said seat, and having movable means for changing the relative positions of said seatwith respectto said collet, a bellows within said housing and and having a chamber communicatively 'con-- nectable to a fluid pressure source and being adapted to actuate said movable means, said bellows being expansible and having an integral wall thereof movable to affect a movement of said movable means to thereby cause the jaws of the collet to open.

3. In a collet-type chuck or the like havinga housing, and sleeve withinsaid housing providing a tapered seat, a collet engaging in said seat,

and having movable means for changing the rela-' tive positions of said seat with respect to said collet, said last means comprising lever means pivoted in said sleeve; an adjusting sleeve secured to the inner end of said collet; a thrust sleeve adjustably carried by said adjusting sleeve, the pivoting of said lever in one direction being adapted to force said thrust sleeve rearwardly to thereby cause said collet to slide inwardly to thereby close the jaws of said collet, the movement of said lever in an opposite direction being adapted to force said adjusting sleeve forwardly to urge said collet outwardly to thereby open the jaws of said collet.

4. In a collet-type chuck substantially as described in claim 3 and having an expansible bellows retained in said housing and being communicatively connected to a fluid pressure source; a movable lock ring frictionally engageable with said lever means, the increase in pressure in said bellows being adapted to cause same to expand to thereby cause said ring to frictionally engage, pivot and hold said lever means in pivoted positions, and having means for disengaging said lock ring from said lever, the disengagement of said ring and said lever being adapted to pivot said leverto thereby permit the jaws of said collet to open.

5. In a collet-type chuck substantially as recited in claim 3 and having a ring slidable on said sleeve and frictionally engageable with said lever and adapted to pivot same; means for causing said ring to frictionally engage and disengage said lever and having an adjusting means comprising a plurality of annularly spaced slots; and having a pin removably mountable in said slots and being adapted to retain said adjusting sleeve from rotation independent of said thrust sleeve, the removal of said pin being adapted to permit adjustment of said collet with respect to said thrust sleeve and said lever means.

6. In a collet-type chuck, a collet; a sleeve providing a seat in which said collet is slidable; movable means for changing the relative position of said seat with respect to said collet, and an expansible hermetically sealed annular housing communicatively connected to a fluid pressure source for actuating said movable means, said housing having an integral wall thereof movable to aiIect a movement of said movable means to thereby cause the jaws of the collet to close or open; a lever actuable by the expansion of said housing and pivoted in said sleeve; and means engageable with said lever whereby said collet may be locked in position.

'7: In combination, ahousing providing achamber; abellowsini saidw chamber and being communicatively connectedto a fluid pressure source; a;lever-actuable by; the expansion of said; bellows asli'dable sleeve engaging said lever and vadapted'to besmoved thereby; a collet operalti yelyqconnected t0:said s1eeve; means providing aseat for said collet; the movement of said sleeve being" adapted tocause said collet to move againstthe walls-of said seat to thereby cause a jclosingof the jaws-of saidcollet and means ena eabl'e with: said lever-for locking it in collet closed :position;

8. In a collet-rtype chuck having a housing, means Withinsaidhousing providing a seat, andhaving, a movable means within said housing for changing the relative positions zof said seat and collet and being: characterized by. anexpansible means; an integral Wall of which is movable,v said eX-pansible means being communicatively connectabletoafluid pressure source whereby said movable means maybe-movedto thereby cause theflaws of the chuck to:open, or close.

" 9; .In-:-. a colletetypm chuck: substantially at:

defined :in claim-- 8 being 5 further. charaeterizedi by a v locking means: for locking; said movable:

means whereby the;retraction of said-:expansiblea means will not =a-ffectwthe =movab1e=meansz EDWARD G. sMITKA.

REFERENCES; CITED The followingreferences are of record inthe file of this patent? UNITED STATES i PATENTS 

